A little less than 5 years ago, editor Betsy Mason of WIRED Science called to ask whether I’d be interested in joining a new thing. WIRED was thinking about starting a science blog platform; she wondered whether I’d want to be one of the bloggers.

I did very much want: WIRED is both a great magazine, with inspiring storytelling and innovative design, and a brand with international reach. I was a bit perplexed why they would want me — scary diseases didn’t seem like a core interest for WIRED readers — but Betsy (now one of the authors of WIRED’s Map Lab blog) was confident the audience was there.

She was right. Superbug debuted Sept. 14, 2010 with a report on the “Indian superbug,” the antibiotic resistance factor NDM that was then just starting to move across the world. My second post explored “livestock MRSA,” the bacterium that originates in antibiotic overuse in agriculture, and the third looked at the shivery subject of a rare and deadly parasite transmitted by organ transplants. Those three posts pretty much defined Superbug’s turf: public health, global health, and food policy, with a sprinkle of dread. Readers responded with fascination and good will, then and to the more than 300 posts afterward.

Of which, as you’ve probably guessed, this is the last. Superbug has had a fantastic run, but there was only one other place I wanted to work, and I’m headed there. Next week, I’ll be joining National Geographic’s Phenomena under a new blog name.

(Worth saying: This move is coincident with Wired.com’s redesign, but is not at all related. Phenomena happened to have a rare opening.)

A Pakistani health worker administers polio drops to a child during a polio vaccination campaign in Karachi on January 20, 2015. Rizwan Tabassum/AFP/Getty Images

Time to check in on another globe-spanning epidemic. While we were all watching Ebola, polio continues—and as long as it does, it holds the possibility of surging back over the rest of the world.

A quick refresher: Polio has been the target of a very expensive and aggressive multi-national eradication campaign since 1988. By last summer, polio was endemic—that is, transmission from one person to another has never been interrupted—in Afghanistan, Pakistan and Nigeria. Very high rates of vaccination have kept the paralyzing disease from leaking over those countries’ borders to most of the rest of the world—but every once in a while, something slips through, or a country runs out of money and lets its vaccination campaigns lapse.

As a result, last year, there was still polio in seven other countries — Cameroon, Equatorial Guinea, Ethiopia, Iraq, Israel, Somalia and Syria—and the World Health Organization declared an international emergency.

So, updates: Despite its ongoing civil strife, Syria has not had a polio case in a year. There has been no detection of polio virus in sewage in Israel or the West Bank or Gaza since March. It has been almost 6 months since the last polio case in Nigeria—extremely good news because that country has periodically re-infected other areas of Africa.

Unnerving news from Brazil, now hosting travelers from all over the world because of the World Cup: The virus that causes polio has been found in sewage in one of the cities where matches are being played.

The World Health Organization, which announced the finding on Monday, says the virus was discovered last week in a sample collected in March at Viracopos International Airport in Campinas, which is about 60 miles outside Sao Paulo, and is where many of the World Cup teams have been landing. The agency said no cases of polio have been identified and there is no evidence the disease has been transmitted.

Genetic sequencing of the virus—the WHO didn’t say, but probably done by the Centers for Disease Control and Prevention in Atlanta—revealed that it was closely related to a poliovirus that recently caused a case of the disease in Equatorial Guinea in West Africa. Humans are polio’s only host; so that probably means the virus was carried into Brazil by a traveler, likely someone who never knew he was harboring it.

Brazil, like most of the rest of the world, continues to vaccinate against polio, even though there have been no cases of polio in Brazil since 1989, and the Americas were declared polio-free in 1991. The high vaccination rate — 95 percent of children nationwide, and higher than that in Sao Paulo State — kept the virus from spreading.

There’s news out this week that feels almost impossible to deliver without an eyeroll: The CIA has promised that it will “never again” use an international vaccination campaign as a cover for intelligence gathering.

In a move that is simultaneously discouraging, urgent and deeply unusual, the World Health Organization has declared that the resurgence of polio is a “public health emergency of international concern.” It’s an extraordinary statement, coming less than four months after India — once considered a place where polio might never be vanquished — was declared polio-free after three years without a new case.

That achievement left only Afghanistan, Nigeria and Pakistan as countries where the chain of polio transmission had never been broken. But as the virus persists in those countries, it is also moving out across their borders. Seven other nations that previously had beaten polio — Cameroon, Equatorial Guinea, Ethiopia, Iraq, Israel, Somalia and Syria — have now been reinfected, and the virus is spreading in communities there.

If the continued existence of polio is news to you, you’re not alone. It’s a largely forgotten disease in the industrialized West; the last United States case occurred in 1979. The WHO, the Centers for Disease Control and Prevention, the fraternal organization Rotary International and a raft of partners have been pressing an international and very expensive eradication campaign since 1988. Every time the world has gotten close, though, polio has flared up again. The WHO once thought it would be able to declare the disease eradicated in 2000; then it set 2005 as a target; then 2008; 2012; 2015; and now, a hoped-for 2018. (Here’s my archive of posts.)

But the past couple of months have thrown even that into doubt. The trigger for the WHO’s action was the discovery that there have been 74 cases of polio so far this year. That seems like a low number, but there were only 417 in all of 2013. And, crucially, winter is considered polio’s “low season” — so for polio to be spreading now rings an alarm bell for the warmer, wetter months when it usually spreads faster and further.

When last we left the long asymptote of polio eradication, nine health workers in Pakistan who had been administering polio vaccine had been murdered, presumably by the Taliban or its sympathizers, because polio eradication has been cast by them as a plot against Islam in the wake of a CIA operation which used vaccinations as an attempt to get close to Osama bin Laden.

(If this story is new to you: Yes, really. For background, start with this post, and then read this, this, and this.)

So it’s discouraging to say that, in the past few weeks, the news hasn’t gotten any better — though some additional voices have joined the debate in an attempt to stress to the world how important this moment is.

There is news today, confirmed by severalmediaoutlets and also by the World Health Organization and UNICEF, that six people working as polio vaccinators were murdered in three separate coordinated attacks in Pakistan. While no one has yet claimed responsibility, it is widely assumed that the attackers have ties to the Taliban, which has opposed the polio-vaccination campaign as a Western plot and accused vaccinators of working as spies for the CIA.

This is grievous and appalling. Infuriatingly, it was also predictable. Constant readers will remember that, back in 2011, the CIA did use a vaccination campaign as a ruse to attempt to to find Osama bin Laden. The unsuccessful attempt was denounced all over the world for putting the polio campaign at risk, and news sources within Pakistan quickly began reporting that vaccinators were feeling threatened. Adding to the sense of threat, a Taliban commander blocked the campaign in one province last June, a United Nations doctor and his driver were fired on in July, and a vaccinator was executed in October by a man who roared up on a motorbike and dashed away.

Regular readers will remember my outraged rantpost from almost a year ago, reacting to the news that the Central Intelligence Agency faked a vaccination campaign in Pakistan as a way of getting close to Osama Bin Laden’s hide-out, hoping to prove his presence by using a vaccine needle to grab a sample of DNA.

I felt, and still feel, that the maneuver — which was belatedly acknowledged by the CIA — was a cynical attempt to hijack the credibility that public health workers have built up over decades with local populations. I especially felt it endangered the status of the fraught polio-eradication campaign, which over the past decade has been challenged in majority-Muslim areas in Africa and South Asia over beliefs that polio vaccination is actually a covert campaign to harm Muslim children — an accusation that seems fantastic, but begins to make sense when you realize some of those areas have perfectly good reasons to distrust vaccination campaigns.

An independent monitoring board convened by the worldwide polio-eradication initiative has delivered a report on the global effort that is striking for its brutally frank and even frustrated tone.

Among its findings, just in its first few pages: “Case numbers are rising”; “unwelcome surprises continue”; “as many milestones are being missed as are being met”; and “the (eradication) Programme is not on track for its end-2012 goal, or for any time soon after unless fundamental problems are tackled.”

Possibly the biggest problem, the board concludes, is a get-it-done optimism so ingrained in the 23-year effort that it cannot acknowledge when things are not working:

We have observed that the Programme:

Is not wholly open to critical voices, perceiving them as too negative – despite the fact that they may be reporting important information from which the Programme could benefit.

Tends to believe that observed dysfunctions are confined to the particular geography in which they occur, rather than being indicative of broader systemic problems.

If some of this sounds familiar, that is because the board hit similar notes in its last report in July, in which it declared that the international effort “is not on track to interrupt polio transmission as it planned to do by the end of 2012.” I get the sense, reading the latest, that the board does not believe it was heard.

The generally accepted math, in polio detection, is that one verified case of polio paralysis represents up to 200 cases of silent infection. Those 200 undetected cases may not experience symptoms, but they can pass on the disease to others. As a result, one case of polio in an area that has been considered polio-free is an emergency. Four cases, as you can imagine, is much worse. [Read more…]